SURFACE ACTIVITY AND HYDROPHILE-LIPOPHILE BALANCE OF HYDROPHILIC POLYMERS FROM EXUDATES OF CASHEW AND KHAYA PLANTS
The surface activity and hydrophile-lipophile balance of cashew gum (CSG) and khaya gum (KYG) were evaluated and compared with those of standard acacia gum B.P (ACG). The surface tension of low concentrations of the gum dispersions was evaluated; and the critical micelle concentration of each gum was determined. The hydrophile-lipophile balance (HLB) values of the gums were also determined sequel to the determination of their moisture sorption capacity, solubility, phenol index and partition coefficient. The polymers showed comparable and moderate surface activity but different critical micelle concentrations with ranking as: ACG < CSG < KYG. The viscosity of 2 % w/v polymer dispersion was in the order: KYG > ACG > CSG. The HLB values were 14.10, 15.91 and 16.09 respectively for ACG, KYG and CSG. Cashew and khaya gums possess moderate surface activity with oil-in-water emulsifying property. Concentration of 0.50 % w/v for cashew gum and 0.75 % w/v for khaya gum in absorption compartment might be the minimum to achieve good absorption of poorly soluble drugs. Also, these concentrations might be the maximum to achieve good absorption of highly soluble drugs. The two polymers possess solubilizing property based on their HLB values